Keep the file download default unless you're having trouble with it - KFC usually keeps it updated and online.

For, you want to use a stratum pool. For WeMineLTC, use:
stratum+tcp://gigahash.wemineltc.com:3334

Other pools have very similar URLs, just a different name and port.

Afterwards, go to "My Workers" on your pool. It should look something like this:

Now go back to Plasma RAT and put in your user information. My worker name is "Understalker.1", so I put in "Understalker.1" for the pool username. My worker password is simply "x", so I put in "x" for pool password.

After that, just hit "Start Mining" and your bots will start mining! You can select "Send Miner to Bots as they Connect" to send the miner command to new bots and such, so if you're buying bots to make money, it works automatically!

This is an amazing RAT, I recommend it to everyone looking for a stable, powerful RAT that is great for making money and DDoS!